I'm not an expert, but I've been working n the same area. If someone knows better than me, please correct me if I get this wrong!
Pre Load - This will not alter the height of the forks, only the amount of tension the spring is under without any other load. As the spring compresses (as the forks dive) the resistance to any further compression increases. If you want less dive, then increase the preload.
Rebound damping - When the compression force is removed (you stop braking) the spring will want to expand again. The more it was compressed the greater the force it will want to expand with. Rebound damping controls the rate at which the spring is allowed to expand. It can't change the force involved, only the rate at which the spring expands.
Compression damping - Is the opposite of rebound. It controls the rate at which the spring is allowed to compress. The forces remain the same, it is the amount of time the spring will take to compress to the point where it has compressed to take the load of the applied force.
So ... If the dive is too much you can increase the pre-load - thereby stiffening the spring and it will take more force to compress it further. The downside of this is that smaller bumps in the road will not be absorbed by the spring and you get a juddering ride. Increasing the compression damping will slow the rate of compression. Perhaps compression damping (slower compression) is what you are looking for.
The process I went through (I'm 6 feet and 90Kgs) was to set everything to factory standard - front and rear - and then make small changes, front and rear. Don't go chasing a setting and ideal only change one setting at a time. If it doesn't make the improvement you are looking for, put it back to where it was before and try something else. Small changes and ride the bike 15-20 miles to test the results.
I found that for me (just me and the way I ride) 3 clicks more preload on the rear and one-click less compression damping (to remove chatter over uneven road surfaces)was what I wanted.
Tin hat on
happy to be corrected.